It is now well-documented that the amygdala complex plays an important role in learning and memory processes. Assuming that learning and memory are a consequence of enduring neural changes, not only in the amygdala but within an entire system, then using the amygdala as a focal point, the elucidation of the involvement of specific amygdala components and their fiber connections in learning and memory processes is a necessary prerequisite for determining (1) the exact nature of the enduring neural change and (2) the exact role of the amygdala in these processes. Our proposed research is directed toward the long-term goal of determining the specific amygdala neuroanatomical systems which contribute to learning and memory processes. To this end we have chosen initially to study the effects of (1) beta-adrenergic blockade and discrete lesions of the central nucleus of the amygdala on the aquisition of conditioned nictitating membrane and heart rate responding and (2) post-conditioning beta-adrenergic receptor blockade of the central nucleus on time-dependent memory processes in the New Zealand rabbit. The rationale for investigating the central nucleus and for selecting our behavioral paradigms, experimental animal and brain manipulative techniques are more fully described in the proposal. It is predicted that the results of these experiments will present a more detailed analysis than formerly available of the involvemnt of specific amygdala nuclei and their afferent and efferent systems in the mediation of both somatic and autonomic conditioned and unconditioned responses as well as the involvement of these components in time-dependent memory processes.